Quasi contracts are frequently referred to as equitable in character.2 And they are equitable in the sense that, unlike most legal obligations, they rest not at all upon formal conceptions inherited from the days of more primitive law, but solely upon the universally recognized moral obligation of one who has received a benefit, the retention of which would be unjust, to make restitution. But they are legal obligations, rather than equitable, in the sense that they originated in the courts of law and are enforced by means of so-called legal as distinguished from equitable remedies. It is true that courts of equity, in the exercise of their jurisdiction to reform and rescind contracts, frequently enforce obligations to make restitution, but such obligations, while similar in many respects to those enforced at law, are not commonly regarded as a part of the law of quasi contracts and will not be treated in this book. Sec. 7. (IV) Essential elements of quasi contractual obligation. - In order to establish the existence of a quasi contractual obligation it must be shown:

1 Ames, "History of Assumpsit," 2 Harv. Law Rev. 53, 63; Select Essays in Anglo-American Legal History, Vol. Ill, 259, 292: Keener, "Quasi-Contracts," p. 15.

2 See, for examples, Moses v. Macferlan, 1760, 2 Burr. 1005; Western Assurance Co. v. Towle, 1886, 65 Wis. 247; 26 N. W. 104.

(1) That the defendant has received a benefit from the plaintiff.

(2) That the retention of the benefit by the defendant is inequitable.

There are certain cases, moreover, in which, notwithstanding the presence of both of the above elements, the courts refuse, on grounds of public policy, to recognize a legal obligation (post, Sec. Sec. 87, 135, 156, 161, 187, 190).